This invention is directed to a collapsible plastic tube excellently adapted for preparing collapsible packaging and dispensing tubes for foodstuff such as mustard paste, ketchup, chutney, mayonnaise, and the like. The collapsible plastic tube of this invention is also excellently adapted for making packaging and dispensing tubes for items such as toothpaste, shaving cream, lubricating greases, medicinal pastes, ointments, and the like. Other materials which can be packaged in said collapsible tube and other uses for said tube will be readily apparent to those skilled in the art.
It is well known that when a portion of a material such as mustard paste, ketchup, shaving cream, or the like is squeezed out of a metal (e.g., tin or aluminum) packaging and dispensing tube, the tube remains collapsed and does not reexpand and does not suck air into itself (the tube) when pressure thereon is released. It is also well known that, when a portion of ketchup (or the like) is squeezed from a conventional plastic packaging and dispensing tube, the tube reexapnds when the squeezing pressure is released. On reexpanding air is sucked into the plastic tube. The thus included air is expelled along with the ketchup when a further portion of ketchup is squeezed from the tube. Expelling such air along with the ketchup can cause the ketchup to "spray" onto one's clothing and/or onto other people. Also, included air can cause contamination and oxidation of material in the tube with consequent deterioration.
Dispensing and packaging tubes (such as toothpaste tubes, ketchup tubes, and the like) made from the collapsible tube of this invention remain collapsed and neither reexpand nor draw in air when; (a) a portion of material (e.g., ketchup, chutney, toothpaste, shaving cream, or the like) contained therein is dispensed therefrom by squeezing with gentle pressure; and (b) the squeezing pressure is released. Hence said collapsible tube is an excellent replacement for metal tubes for packaging items such as ketchup, mustard paste, chutney, shaving cream, toothpaste, and the like.
U.S. Pat. No. 3,491,799 (Foll, 138/137) and U.S. Pat. No. 3,600,487 (Zavasnik, 264/89) teach methods for preparing laminated plastic tubes.